Scientists have discovered what they claim to be a major piece in the puzzle of dinosaur-to-bird evolution: a cat-sized fossil that they call "the most birdlike dinosaur yet discovered." Its name, Bambiraptor feinbergi, tells much of its story. It was found in 1993 by a fossil-hunting family in Montana who nicknamed the juvenile creature Bambi. It was purchased for a reported $600,000 by Florida dinophile Michael Feinberg, who paid to have it reconstructed and analyzed at the University of Kansas, Lawrence.

The long-tailed fossil--a member of the large-clawed, meat-eating dromaeosaur family--is not only a new species but is extraordinary in being almost complete, says David Burnham of the University of Kansas Museum of Natural History. It sports a birdlike wishbone, probably weighed in at about 3 kilograms, and boasted a relatively big brain. It was "as brainy as almost any bird today," says Burnham.

The 75-million-year-old fossil looks "old-fashioned for his time," because some of its features are more primitive than the 150-million-year-old Archaeopteryx, known as the earliest bird, says University of New Orleans paleontologist Kraig Derstler, co-author of a paper appearing this month in The University of Kansas Paleontological Contributions.

Bambi has "a gorgeous little skull," enthuses dino expert Tom Holtz of the University of Maryland, College Park. He says the specimen is likely to furnish missing details about dromaeosaur bones, and it "tells us how successful the dromaeosaur body plan was," as it persisted with few changes for about 100 million years.